ci: setup Renovate for flagsmith-flag-engine tracking (#47)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Zaimwa9

renovate.json

@@ -0,0 +1,26 @@
+{
+    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+    "extends": ["config:recommended", ":semanticCommitScopeDisabled"],
+    "ignorePresets": [":semanticPrefixFixDepsChoreOthers"],
+    "semanticCommitType": "deps",
+    "packageRules": [
+        {
+            "matchUpdateTypes": [
+                "major",
+                "minor",
+                "patch",
+                "digest",
+                "pin",
+                "rollback",
+                "bump",
+                "replacement",
+                "lockFileMaintenance"
+            ],
+            "enabled": false
+        },
+        {
+            "matchPackageNames": ["flagsmith-flag-engine"],
+            "enabled": true
+        }
+    ]
+}